Dolphin Development

From Embryology

Introduction

Dolphin anatomy

Delphinus


Some Recent Findings

  • Seasonality, estrous cycle characterization, estrus synchronization, semen cryopreservation, and artificial insemination in the Pacific white-sided dolphin (Lagenorhynchus obliquidens). [1] "Ovulations and conceptions occurred from August to October. Peak mean serum testosterone, cross-sectional testicular area , and sperm concentration occurred in July, August, and September respectively. Spermatozoa were only found in ejaculates from July to October. Estrous cycles were 31 d long and were comprised of a 10 d follicular and 21 d luteal phase. Ovulation occurred 31.2 h after the onset of the LH surge and 19.3 h after the LH peak."
  • True hermaphroditism: first evidence of an ovotestis in a cetacean species[2] "An immature unilateral hermaphrodite common dolphin (Delphinus delphis) was found stranded on the southwest coast of the UK. The external phenotype was that of a female, but internally there was one ovotestis, containing both ovarian follicles and testicular tubular elements, and a contralateral ovary. Ovarian portions of the ovotestis appeared normal and demonstrated follicular development, whereas the testicular tissue exhibited hypoplasia and degeneration."

Taxon

Suborder Odontoceti, toothed whales

  • Family Delphinidae, oceanic dolphins
  • Family Platanistidae
  • Family Iniidae
  • Family Lipotidae
  • Family Pontoporiidae


Species

  • Common bottlenose dolphin (Tursiops truncatus)
  • Indo-Pacific bottlenose dolphin (Tursiops aduncus)
  • Burrunan dolphin (Tursiops australis)

Development Overview

Limb Development

Hind-limb loss in embryos of the dolphin.[3]

Researchers have identified that Sonic hedgehog (Shh), that in limb development is the signaling activity of the zone of polarizing activity (ZPA), is absent from the dolphin hind-limb bud. An absence of Hand2, an upstream regulator of Shh, leads to the failure to establish a ZPA.[3] The hind-limb bud initiates, but then bud arrests and degenerates around the fifth gestational week.

Dolphin limb development 02.jpg

Links: Limb Development | Sonic hedgehog

References

  1. <pubmed>19494046</pubmed>| Reproduction
  2. <pubmed>20708743</pubmed>
  3. 3.0 3.1 <pubmed>16717186</pubmed>| PNAS

Reviews

<pubmed>10882306</pubmed>


Articles

<pubmed>20722252</pubmed> <pubmed>17957751</pubmed> <pubmed>17597550</pubmed> <pubmed>12845705</pubmed> <pubmed>4856964</pubmed>

Books

Search PubMed

Search PubMed: Dolphin development | cetacean development

External Links

External Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name. Links to any external commercial sites are provided for information purposes only and should never be considered an endorsement. UNSW Embryology is provided as an educational resource with no clinical information or commercial affiliation.

Animal Development: axolotl | bat | cat | chicken | cow | dog | dolphin | echidna | fly | frog | goat | grasshopper | guinea pig | hamster | horse | kangaroo | koala | lizard | medaka | mouse | opossum | pig | platypus | rabbit | rat | salamander | sea squirt | sea urchin | sheep | worm | zebrafish | life cycles | development timetable | development models | K12
Historic Embryology  
1897 Pig | 1900 Chicken | 1901 Lungfish | 1904 Sand Lizard | 1905 Rabbit | 1906 Deer | 1907 Tarsiers | 1908 Human | 1909 Northern Lapwing | 1909 South American and African Lungfish | 1910 Salamander | 1951 Frog | Embryology History | Historic Disclaimer

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2024, June 23) Embryology Dolphin Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Dolphin_Development

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G